833 OD sticking in 4th, chipped synchro

I wasn't knocking your transmission selection.
I myself ran that trans for a couple of years behind a stout 367.
to make it a high-rpm runner, I know what to do
But in the end, I let it go.
BTW;
I want to give you some food for thought:
I am currently using the Commando with ratios of 3.09-1.92-1.40-1.00 / With 3.23s (no longer in the car) the Road gears were;
-------9.98--6.20-4.52-3.23-- if you ran 3.73s with that od box, your roadgears would be
11.53------6.23----3.73---2.72 ; and 65=2475 with a 24" tire. This is actually a pretty good set-up for a slanty
Notice Second gears are the same.
To cruise any slower and still get better fuel-economy would be difficult because of the near impossibility to provide enough ignition advance with the factory type distributor. So that's two gears in your favor.
As for the 11.53 starter gear, while being pretty doggone low, it's a really good parade gear, and a dump-it-and-go starter gear. But Second gear comes along pretty fast. First gears this high are hard to rate, with the small 24" tires. The 3.73 roadgear is pretty good because with it 40 mph is ~2100, a good place to be cruising at in the city. So that's 3 out of 4 not too bad.
You may have other ideas, and that's fine, the real point I'm trying to make is that down below about 2400 it is no longer possible to meet the engines timing requirement, and fuel-economy will begin to suffer because of that. To find out how much timing your engine wants at any cruise rpm, just rev it up to the chosen rpm and read the current advance.
Then, keep giving it advance while simultaneously keeping the rpm at the set point. When the rpm no longer rises with additional advance, read the timing and subtract about 2 or 3 degrees for the load, and that is your magic number. Now put the timing back and return the engine to idle. Finally, compare what the engine wants to what your distributor is currently giving, then figure out if she can be modified to supply the difference.
Don't be surprised to see a requirement of over 50* at 2400rpm.
If you cruise below the magic number, you can expect that whatever savings that the lower rpm might be worth, is lost to the lack of efficiency due to not enough timing. They sorta run neck and neck but in opposite directions.
You can try this at say 200 rpm intervals from 1600 to 2800, then modify your distributor as best as you can, and plot the two sets of numbers on a graph to see where they intersect, and badaboom, there is your optimum cruising rpm.
Now you just have the carb to deal with, lol.
If you really want to cruise below 2200 and simultaneously get optimum fuel economy, then, you will need a stand-alone, aftermarket, dash-mounted, dial-back , timing module. Mine has a range of 15 degrees. or a timing computer.
Happy HotRodding.